Column-clamp.



l. G. ENGSTBOM.

COLUMN CLAMP.

APPLlcATloN FILED MAR. 3|. |915.

23.4,995 Patented Feb. 71191?.

"""lum UIslITED @TATF PATENT @FFIQEO ISACK G. ENGSTROM, Y0F MINNEAPOLIS, MINNESOTA.

COLUMN-CLAMP.

ramena. Y

Application led Mar-ch 31, 1915.

To all whom t may concern:

Be it known that I, IsAcK G. ENGsTRoM, a citizen of the United States, residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain new and useful Improvements in Column Clamps; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention has for its object to provide a column clamp, which, while of simple construction and small cost, is highly eflicient and very convenient for the general purposes had in view; and, to such ends, generally stated, the invention consists of the novel construction and arrangement of parts hereinafter described and dened in the claims.

Particularly, the invention is designed, as indicated, for use as a so-called column clamp to lock together the forms within which concrete columns are molded into shape, but the invention is capable of various other analogous uses. In the drawings the clamp is illustrated as applied to hold together a rectangular column form, and, for such purpose, four clamping bars, pivotally connected in pairs, are employed. When used to hold columns of other polygonal form, a number of clamping bars will be employed equal to the number of sides in the form.

In the accompanying drawings, which illustrate the improved clamp in its preferred form, like characters indicate like parts throughout the several views.

Referring to the drawings Figure 1 is a plan view of two ofthe complete clamps applied in working position to rectangular form of knock-down con-k struction. said form being shown in section;

Fig. 2 is an elevation with some parts sectioned. on the line X2 X2 of Fig. 1;

Fig. 3 is a side view of one of the clamping bar draw heads on an enlarged scale, some parts being shown in different positions by means of broken lines;

Fig. 4 is an end elevation of the parts shown in Fig. 3;

Fig. 5 is a view corresponding to Fig. 3, with the exception that the parts are shown in different positions; and

Fig. 6 is a transverse section, taken on the line X X8 of Fig. 5.

rl`he numeral 1l indicates the four sides of specification of Letters Patent.

Patented Feb. 6, im?.

Serial No. 18,265.

the collapsible column form. As shown, the improved clamp comprises four bars 2 and a pair of draw heads 3. The clamping bars 2 are pivotally connected in pairs by rivets 4. These bars 2 are identical, one with the other, and arel preferably made from flat straight steel with ratchet-like teeth 5 cut in the outer edges of their free end portions. The clamping bars 2 are placed around the collapsible form in rectangular arrangement, with their joints at diagonally opposite corners thereof, and the free end portions of said bars are overlapped, one with the other, at the other corners of said form.

The clamping heads 3 are provided for locking the overlapped ends of the clamping bars 2 together` and frictionally clamping the same around the collapsible form for holding the clamping bars assembled. Each of these draw heads 3 is made up of two flat members 6 and 7, spaced apart at their adjacent edges, in parallel arrangement to adord therebetween a passage 8 for the crossed ends of the clamping bars 2. The draw head member 6 is oi'lset at one edge to alford a shoulder 9 which extends transversely across the passage 8 and forms one end thereof.

Integrally formed with one edge of the draw head 7 is a relatively short leg 10 and a relatively long leg 11. These legs 1() and 11 extend transversely of the draw head member 6 and rest directly thereon. draw head member 7 is connected to the draw head member 6, for pivotal and sliding movements, by a headed stud 12 on the short leg 10, which works in a longitudinally extended slot 18, formed in the end of the draw head member 6, adjacent to its shoulder 9. The long leg of the draw head member 7 extends transversely across the passage 8, forms one end thereof, and affords a shoulder 14 for cooperation with the shoulder 9. Obviously, by sliding the members of the draw head 3, with respect to each other, the shoulders 9 and 14 may be moved toward and from each other, at will. The free end of the leg 11 is bent laterally toward the draw head member 6 to adord a lock lug 15, arrangedto engage the outer longitudinal edge of said member 6 and thereby interlock the members of the draw head 3 against pivotal separation, but with freedom for sliding movement, one upon the other.

As shown, an eccentric 16 is provided for drawing the shoulders 9 and 14 of the draw head 3 toward each other. A stud 17 pivotally connects the eccentric 16 to the draw head member 6 for engagement with the outer edge portion of the leg 11. Rigidly secured to the outer face of the eccentric 16 is a disk 18, having a diameter considerably larger than the eccentric 16, to thereby aiord a flange arranged to overlapY the leg 11 and hold the same in fiat engagement with the draw head 6. By holding the leg 11 against lateral separatio-n from the draw head member 6, the lug 15 is also held in position to prevent pivotal separation of the draw head members, but allows free sliding movement of the one upon the other. Diametrically opposite lugs 19, projecting from the outer face of the disk 18, are arranged to receive therebetween a flat tool, or bar, 20, indicated by broken lines, by which the eccentric may be rotated. A lug 21, on the eccentric 16, engages the draw head member 7 to limit the oscillatory move- 'ment of the eccentric 16.

The draw head 3 is applied around the overlapped ends of the clamping bars 2, rst by pivotally separating the members, as indicated by broken lines in Fig. 3, and then by a pivotal folding movement. During the pivotal separation and folding movement of the members of the draw head 3, it is also necessary to laterally separate their free ends a distance sui'icient to allow the lug 15 to pass the draw head member 6. After the draw head 3 is secured around the overlapped ends of the clamping bars 2, said bars are secured thereby against lateral separation with respect to each other. By insei-ting the bar 20 between the lugs 19,V the eccentric 16 may be rotated in the direction of the arrow marked thereon in Fig. 3, to draw the shoulders 9 and 14 toward each other andv onto the teeth 5 of the bars 2. These teeth 5 hold the draw head 3 interlocked with the bars Q, and also permit the application of the draw head to different longitudinal points on said bars.

The frictional contact between the leg 11 of the draw head members 7 and the eccentric 16 will hold said eccentric against backward rotation, after the bar 2O is removed from between the lugs 19.

IVhat I claim is l. A clamp of the kind described comprising bars having overlapped ends, a twopart draw head embracing the overlapped ends of the bars for drawing said barsendwise one upon thevother and for holdingk the Vsame against lateral separation, the

members of the draw head having sliding Y engagement one upon the other and provided with coperating shoulders having interlocking engagement with the longitudinal edges of the bars, and means operative on the members of the draw head for moving their shoulders toward each other.

2. A clamp of the kind described comprising bars having overlapped ends, a twopart draw head embracing the overlapped ends of the bars for drawing said bars endwise one upon the other and for holding the same against lateral separation, the members of the draw head having sliding engagement one with the other and provided with cooperating shoulders having interlocking engagement with the bars at different longitudinal points, and a cam operative on the members of the draw head for moving their shoulders toward each other.

3. A clamp of the kind described comprising bars having. Voverlapped ends, a twopart draw head embracing the overlapped ends of the bars for drawing said bars endwise one upon the other and for holding the same against lateral separation, said draw head comprising a pair of members having pivotal and sliding movements one with the other andprovided with coperating shoulders having interlocking engage'- ment with the bars', and Imeans operative on the members of the draw head for moving their shoulders toward each other.

4;. A clamp of the kind described comprising bars having overlapped ends, a twopart draw head embracing the overlapped ends of the bars for drawing said bars endwise one, upon the other 'and for holding the same against lateral separation, said draw head comprising a pair of members having pivotal and sliding movements one with the other and provided with cooperating shoul- Vders having interlocking engagement with the bars, a cam operative on the members ofthe draw head for moving their shoulders toward each other, and lugs on *the cam by which the same may be rotated.

5L A clamp of the kind described comprising bars having overlapped ends, a twopart draw head embracing the overlapped ends of the bars for drawing said bars endy ISACK G. ENGSTROM. Witnesses:

EVA E. KNIG, Y HARRY D. KIL'G'OR.

copies f this patent may be obtained' foi- 'ave @ems each, by a'aaressia'g" are f-eommrssonerfof Patents,

Washington, D. C. 

